Eddy-Current Loss Model for Soft Magnetic Composite Materials Considering Particle Size Distribution

Dynamic magnetization curves of soft magnetic materials are often written in terms of magnetic flux density $b$ and magnetic field strength $h$ as $h = \mathcal {H}(b) + c {\text {d} b}/{\text {d} t}$ , where $\mathcal {H}$ is a static magnetization model and $c$ is a real number describing eddy-current effects. In this article, an analytical derivation for $c$ is presented for soft magnetic composite materials. The parameter $c$ will depend explicitly on the conductivity of the material particles as well as the geometry of the particles, described by mean particle volume, variance of the particle volumes, volume fraction of the material and insulation thicknesses. No experimental or empirical parameters appear in $c$ in our treatment.